prob a typo... but the standard is a cross over rules from horus heresy legion rules... which is only for boltguns as in basic bolters.

boltgun/aka bolterboltpistolheavy bolter

I could be wrong tho... This DA codex has a lot of typo problems esp the App store digital one which on the first day had fluff from Vampire counts in one of the entries which was ratified the following day.